Underground The World's Most Extraordinary Homes

I've been picked up from airports in taxis before

but never had to go to a jetty and be picked up by boat.

'He's Piers Taylor, an award-winning architect.'

This building is so tactile and just rich, materially.

'And she's Caroline Quentin,

'acclaimed actress and passionate property developer.'

I've been expecting you, Mr Bond!

'We've been given the keys to some of the most incredible houses in

'the world...'

-It's chock full of surprises, isn't it?

-Ooh!

'..to discover the design innovation,

'passion and endurance needed to transform architectural vision

'into an extraordinary home.'

If this was Hollywood, I'd be snogging you now.

'Together we'll be travelling the globe...'

-Look down there.

-I would but I'm trying not to kill us.

No, you look ahead.

'..meeting the architects and owners who have taken on the challenge

'of building unconventional homes in demanding locations.'

Just another day on the wing of a 747.

'Whether it's navigating the logistics of constructing a house

'on top of a remote mountain...'

Why would you build a house where you can only get there

by cable car?

'..negotiating the ancient trees of a fragile forest...'

You never see a building this close to the trees,

I mean, that's six inches away.

'..having a sea view whilst perched on the edge of

'a dramatic coastal shoreline...'

I'd love to know how you actually built this on what appears

to be a sort of vertical cliff face.

'..or excavating the earth to build a home deep underground.'

No-one had ever built something like this before.

It's a tightrope you're walking. It can go spectacularly wrong.

Building a subterranean house embedded in the earth can provide

an intriguing and magical living experience.

Look how thick that bit of ground is.

This is another world in here.

But unearthing the landscape in order to build these ambitious homes

is a path few dare to tread.

There is always a moment when you feel fear.

Nature is never to come back the same way.

Caroline and I will be travelling from the undulating foothills of the

Southern Alps of New Zealand...

We had to use explosives to blow it all out.

..to the sweeping green valleys of Switzerland.

So, did you have a budget in mind when you started this build?

Yeah, but we didn't make it.

And from the lowlands of a Dutch nature reserve

to the coastal farmlands of the Greek islands.

The architects and I threw up our hands and said, "Do you know what,

"it just isn't working."

Discovering what it takes to design,

build and live in the world's most extraordinary underground houses.

Construction is stressful, it's tiring.

It was hard labour and a lot of blood, sweat and tears.

'The first stop on our discovery of underground architecture takes us to

'the Aegean Sea...'

THEY LAUGH

'..and to the Greek island of Antiparos.'

You love Greece, don't you?

I love it. I've been coming to Greece for 40 years

and I think it's about my favourite place in the world.

I think it's the colour of the water,

the colour of the sky and, still,

-it's so unspoilt.

-Little white squares still.

-Yeah.

-Exactly as you imagined it's going to be.

There's nothing big, nothing breaking the skyline.

There's a rule here that you can only build

so far in one direction before you've got to turn or break it down.

Oh, I see, and that explains all the little boxes. I see.

These, historically, would have been fishermen's houses

and probably a bit of subsistence farming.

'We're heading to a spacious underground holiday home

'where the owners wanted a contemporary house

'big enough to entertain their family and friends.'

The challenge facing the architects was to design a house with stunning

sea views from each of its nine bedrooms.

But, at the same time, discreetly conceal the building.

I mean, I know we're going to go and see, rather bizarrely,

an underground house here.

-Yeah.

-Which I think is a really odd choice given that

this is some of the most beautiful landscape I've ever seen.

A view is a two-way responsibility and actually if you build on that

to look at the view, you also have to accept that you are making

something that people will look at.

Yeah. But presumably that's why they've taken this underground option.

-Yeah.

-So that, something like 80% or 90% of this house is underground,

which sounds hideous to me because I'm slightly claustrophobic

and I can't bear the thought of being underground.

But I think this house is actually designed as a piece of landscape

rather than a building.

So you don't think it's going to be dark, and dingy, and damp?

-I hope it isn't, and it would be a real shame if it was.

-Yeah.

'Helping us locate this coastal hideaway is Theo,

'who looks after the owner's home for them whilst they're back in the UK.'

-Welcome to Antiparos.

-Thank you very much.

THEY GREET EACH OTHER IN GREEK

We're going to go over to that hill and then down again.

I'm assuming we're not going to get a great big vision of the house

because we know that it's 80% or 90% under the ground,

so will we see it at all before we get there?

You'll see it. It's a bit of a surprise, really.

-Is that the house? Oh, my Lord.

-Wow.

What a spot.

SHE LAUGHS

Oh, what a beautiful place!

It's beautiful.

SHE SINGS A HIGH NOTE

I know, I know.

'By hiding the majority of this structure beneath the landscape,

'the architects managed to create a huge house on this site which both

'embraces the view and retains the natural charm of this location.'

Now, the owners are not here but they're very happy for you

to have a look around.

Thank you so much. Thank you so much, Theo, it's really, really kind of you.

Enjoy your time and I'll see you later.

Thank you very, very much.

So, Caroline, tell me now, looking at this,

are you still worried about feeling claustrophobic down there?

Not yet. Not yet, but I'm not making up my mind,

I'm not making up my mind yet.

But, look at it, it's extraordinarily beautiful.

This concealed home sits on a generous six-acre plot.

Around 9,000 cubic metres of earth was excavated from the site,

creating a giant crater.

A concrete foundation and rear and internal walls

were then built in this void, ten metres deep.

The building unfolds on two levels

to allow space for multiple bedrooms,

bathrooms and terraces with private sea views.

Concrete shafts rise up from the rear of the building

to allow ventilation and natural light

to enter the underground spaces.

To fit in with the local architecture,

Ktima's traditional white walls change direction

after every ten metres.

The green roof is covered in indigenous plants,

allowing the underground living spaces to be invisible,

with only the pool terrace and whitewashed walls on view.

These walls look really enticing, don't they?

-How are you with heights?

-Not as good as you.

You should come up, it's great. Look.

-OK.

-Caroline,

there's all these lovely little terraces and courtyards within here.

That's such a private space, as well.

-And there'll be another one there.

-Yeah, another little private space.

God, that's clever, isn't it?

It's a real sense of sort of intimacy, isn't there?

You could be naked reading a book all afternoon.

There's a thought.

This is such a lovely, enticing space.

I mean, look at this, I don't know whether I'm inside or outside.

I thought this was just a canopy of bamboo covering, this space,

but actually there's glass up there so you can sit here even when it's raining.

I mean, look at these walls and shapes and the shadow and

the shade, it's so beautiful.

And looking back through there, Caroline, to the sea.

Yeah.

This is the dream for me, this is absolutely the dream.

It's a kind of, sort of, lesson

in how to build a villa in a hot country.

What I admire about the building is that it's a very clever bit of

architecture, it's very thorough and really well-integrated with

this place and that's why I warmed to it so much.

'By hiding this modern whitewashed house in the landscape,

'it not only retains the island's architectural heritage,

'it also benefits from traditional methods of keeping living spaces cool underground.'

I really want to have a nosy upstairs,

just work out how it all fits together.

I really want to have a peek about in here.

-I'll catch you later.

-OK.

This feels obviously like a really contemporary house

but, at the same time, it has the qualities of something

that's really ancient because people have been building in hot countries

like this for hundreds and hundreds of years.

What they've been doing is building in a way that harnesses

the qualities of the ground, and, under the ground,

is a stable temperature,

so all of the living rooms in this house are under the ground.

What happens then is that that lovely cool sea breeze

is used to draw air through those rooms and then out of those shafts,

those light shafts that are behind.

And those shafts also bring light to the back of the rooms that would

also be dark.

Unlike a normal house where you have light coming in from both sides,

an underground house can't do that, so you need to bring in light.

This is actually the deepest underground

that this house gets and, look, really light.

I think for many years as architects we forgot how to do buildings that

really spoke of their place.

But this building shows that you can harness ancient technologies and

still do a building that is totally contemporary.

I'm loving this, I'm loving this over here.

All it is

is a little bit of light coming down but it's painted orange,

so it just shines out neon, and, up there, all I can see is the bright,

bright blue of the sky against the orange.

It's so beautiful.

SHE SIGHS

All my misgivings about an underground house

being gloomy, and dark, and dank have completely disappeared

because this is light, and bright, and cool,

because it's really, really hot out there.

And it's just perfect temperature in here.

Oh...

It's got a lovely en suite.

Hi, Caroline!

THEY LAUGH

You going to turn the shower on?

-Yes.

-You might take your clothes off first, but...

The view from here is so Greek, it couldn't be more Greek.

It's white walls and then there's a blue dome but the blue dome is made

out of sky.

This is like some ancient Greek hilltop town, isn't it?

Where the buildings are really

close together and all you get is that fantastic view of the sky

through the white walls.

It's wonderful. It's so kind of refreshing down here as well,

you don't feel like you're baking in the hot sun.

Because actually this is a device to bring the air through

and get the light in.

The owners of this underground holiday home live in the UK

with their two children.

Karima is in London,

so I'm giving her a call to find out what drew her family to this island.

Did you fall in love with it straight away?

'Straight away. Straight away.

'Love at first sight.'

-Really?

-'My husband and I,

'I think we were just about to be married

'and we looked out at the sunset

'and that was it, we said we need to see this sunset

'till the day we die.'

Oh, my God, that's so adorable!

But, in purchasing the land,

the couple had also bought into plans for a proposed building

for the site, which had already been designed

by Portuguese architects Camilo Rabelo and Susana Martins.

So, you designed this for somebody that hadn't bought it,

I mean, this was a speculative house for somebody.

It's an abstract problem.

-Yeah, yeah.

-It was like a bridge.

It had a void below the structure and you could see through.

'The plan was a beautiful plan but it wasn't a plan that

'suited us as a family.

'It was quite thin and quite narrow and we live in a tall,

'thin house in London

'and we were very keen to have something with a bit more space,

'a bit more light and air.'

They wanted a bigger house.

How big?

-Double.

-Double.

And this started to change everything.

'We spent a year working on those plans.

'We kept changing them but it just...

'it didn't work with the dimensions and the scope that we wanted,

'it was frustrating.'

Was it ever stressful?

Stressful... Demanding,

let's put it like that, because it was a lot of back and forward.

'And, in the end, the architects and I sort of threw up our hands and

'said, "Do you know what, it just isn't working."

You had to abandon one idea, and how did that feel for you?

At the beginning, we were not very happy but...

It's always difficult to abandon an idea.

And how long did it take you to get to a scheme

that was recognisably this?

-A minute.

-Really?

-Can you show me the first sketch?

-Yes.

-I'm interested in that.

First sketches are often the purist form of an idea.

We started with two broken lines.

Also very basic thoughts.

Like, for example, the Greek amphitheatres, so...

panoramic places for you to enjoy the view.

What's interesting about this, though,

is that it's absolutely the opposite of the previous scheme,

which was a bridge hovering above a piece of landscape,

whereas this is a piece of landscape.

It allows you to conceal a very big building very subtly, but it looks,

now, like a very finished building.

The landscape is all grown back.

But, actually, there must have been huge disturbance to make

this building, huge disturbance to the landscape?

In the beginning, I was very scared when they started the excavation,

-yeah, very scared.

-It's a massive quarry, and it's huge destruction...

There is always a moment when you feel fear, and that is the moment,

when you see this immense crater,

you say nature is never to come back the same way.

But then, it's our role, we are architects.

Architecture means to construct, to build.

There is no visible structure here,

but, tell me, how was it constructed?

These walls are three-layered bricks.

-Traditional brick?

-Traditional brick, which...

-How thick?

-It's about 70 centimetres.

And this is very good, for thermic reasons.

This is the way they build here in Greece.

Very thick walls, with deep reveals, with windows pushed right in.

'When the drawings came to life, and the structure was built,

'there were angles I could not have imagined. I knew the footprint of

'the building and drawings back to front,

'but when you looked at certain angles,

'just...it was beyond, it was beyond what we'd hoped and imagined.'

Standing back now, several years later, do you love this building?

I love this building. Totally love this building, yes!

This is what Karima fell in love with,

as she and her husband saw this plot of land, and, looking at it now,

they haven't made a mistake, have they?

No, I mean, this is, for me, what Greece is about,

this time of the evening, but facing west, getting the sunset over water.

I defy anybody to look at this view

and not think they've found paradise.

Could you sell up and come here?

I think I could, but you'd have to build me a house.

-Deal.

-OK.

Yes!

This view is something

that would make me leave my south-west leafy patch at home.

If this was Hollywood, I'd be snogging you now.

The next stop on our underground adventure

takes us to the lush valleys of the Swiss Alps.

-Oh, look down there!

-I would, but I'm trying not to kill us.

No, you look ahead!

'We're heading to the village of Vals,

'perched over 1,000 metres above sea level,

'and surrounded by alpine pasture land.'

Look at these little dotted about, little shelters...

I think this is it, actually, this is Vals. Here we are, Vals.

Beautiful little buildings, aren't they?

I mean, look up there, Caroline,

these little barns built into the hill.

The only thing I know about these little chalets and things

is that I make one every Christmas out of gingerbread.

Look at that little window!

That's ridiculous. If Hansel and Gretel aren't in there,

I want my money back.

Although we're in the heart of Switzerland,

the underground house we're looking for is

owned by Dutch architect, Bjarne Mastenbroek.

Wanting to push his creative boundaries

and live out his childhood dream,

he built an underground den as a holiday home for his family.

Bjarne found a small, mountainside plot of land,

but it came with a caveat -

he had to keep the traditional agricultural

barn, which existed on the site.

Piers, this is what we've been talking about,

these are the traditional farm buildings,

and these would have had the animals underneath,

and the heat would have been rising up and drying out the hay.

But, of course,

as in everywhere in the world now, animal welfare have become involved,

so these are no longer available...

CAROLINE IS DROWNED OUT BY MUSIC FROM THE SOUND OF MUSIC

..monolithic...

Just a tragic waste...

Oh, dizzy!

'Halfway up the hillside,

'we stumble upon the old barn we've been looking for.'

Well, this is the entrance.

-Yeah.

-So somehow, underneath this, is our house, or...?

Yeah, well, I think we go into it, and then we'll discover it.

It's very mysterious, isn't it?

-Shall I open it?

-Yeah.

-Ooh.

-There's some hay.

It's really exciting!

God, look at it. This is insane.

Rather than get rid of the old farm building,

Bjarne converted it into the entrance for his underground home.

Talking about how to combine modern and ancient agricultural buildings,

this is like a masterclass in that, for me.

It is, it totally is.

-I mean, look at that concrete.

-That's concrete, isn't it, yeah.

Yeah, and just the bare light fittings.

And look at that, that is the tunnel, I think,

that takes us into the house.

Spooky, dark corridors

and being underground, I don't really like very much,

but I can see light at the end of that tunnel.

It feels like we're entering church.

Or a catacomb. I'll tell you what it reminds me of, actually,

is when you go into the pyramids in Egypt.

-Yeah.

-Where they draw you down into the earth.

Yes. This is beautiful.

That's lovely, isn't it?

It feels like it's been here for thousands of years.

And this slot of light here.

I think it's really theatrical, I mean,

the whole orchestrated entrance that leaves the world behind,

and brings you into a sort of secret world.

But it's also just beautiful material,

beautiful light, beautiful angles.

And then, just there, look, the little finials and doorknobs.

-Yeah.

-To hang your coat on.

They're hilarious, aren't they?

Wow! I mean, the shaft of light there is just so lovely.

-Look at that.

-Oh!

Isn't it ridiculous, Piers, that that's so small, and so exciting.

-Yeah.

-It's just a little slash of light through concrete.

Why should that be so thrilling, but it is thrilling, isn't it?

I'm coming out in goose bumps.

As we find daylight again,

the concave facade of the main house

and its panoramic views are revealed.

This is extraordinary, isn't it?

'The deceptively spacious living room is a complete contrast

'to the entrance tunnel.

'Despite being underground,

'the space is flooded with daylight and not at all what I'd expected.'

I have never seen you ever sit down in a house when we arrive.

I think, in a way, it's because that whole experience has been so

carefully orchestrated, the barn, that fantastic hall,

that when you come to this point,

so I'm ready to sit and just kind of drink it in.

I mean, it's a stunning sitting room.

This would do me.

The starting point for building this underground home

was to dig a void 36 feet deep into the hillside,

big enough to enclose this two-storey,

four-bedroom house.

A thick, reinforced retaining wall was then poured,

and internal walls were built from concrete.

The front of the house is sealed by a concave facade,

made from local stone,

and scattered with windows to allow light

into every room of the property.

A 22-metre underground tunnel

connects the house to the barn entrance.

To find out more about the inspiration

for this award-winning home,

we're meeting the owners, Bjarne and his wife, Katrin.

-Hi, there.

-Lovely to meet you.

-And who's this?

-It's Joanne.

Joanne, hello, darling!

I've got to start by saying this is an extraordinarily beautiful house.

Bit unusual, but...

What made you decide to build an underground house?

When I was young, I built a lot of underground huts with my friends,

and that idea I always kept in my mind.

-Yeah.

-So I thought it would be nice to do it,

and here it was quite obvious, because of the steep hill.

I hope you don't mind the way I think of this house, but I feel,

it looks to me like a meteorite or a big cannonball has hit,

and then you pull it out, and you're left with this perfect circle.

And then inside that circle, you built a house.

It's a perfect circle, under 45 degrees,

so the projection of it is an ellipse.

The design of this house reminds me of homes for burrowing animals.

Inside, the maze of rooms feels just like a warren.

I wouldn't be surprised to see a rabbit.

The layout may flow seamlessly now,

but fitting a four-bedroom house in a small hole in the ground

was a huge challenge for Bjarne.

We spent a lot of time on the layout.

First, it was like a banana-shaped building, three stories,

but we had to cut it down all the time, also because of budget,

until we reached, like, two, two-and-a-half stories,

and much more un-deep,

so then you have to organise all the rooms

so that they can have daylight.

That was probably the trickiest thing to get in.

The design of the house as an overall design took a lot of time,

and then we started building, but that took also more than two years.

And how evolved was the design when you started building?

Was it absolutely finished, or...?

No, no, not at all.

So, we also accepted mistakes.

Maybe you will see in the tunnel there is one skylight

that has a real bow in it,

so something went wrong, and then you come here,

and the contractors say, "Oh, I'm very sorry, I have to take it down."

I say, "Oh, no, it's fine, keep it."

And then he's looking at you like, "What? Can I keep it like this?"

Because it's not perfect.

-How amazing.

-You know, we don't want to have it perfect.

My idea is that, for architecture, you don't need perfection.

In a way, perfect architecture tends to become very boring.

Although Bjarne was relaxed during the complex build of this underground house,

there was one aspect that he wouldn't compromise on.

He was adamant about using a local construction team,

out of respect for the area.

To buy a cup of coffee is massively expensive here.

Is it massively expensive to use Swiss builders?

Yes!

-It is.

-So did you have a budget in mind when you started this build?

Yeah, but we didn't make it.

You didn't make it by what, a little or a lot?

A lot. You know, I think we ran over budget about two-and-a-half times.

Did the villagers take to the idea of you building it,

because it's so unlike anything else around here?

I think in the beginning they didn't believe it would ever be built.

It was like it's too crazy, they won't be able to build it.

-What, they didn't think you could do it?

-Yeah.

They said later on, when it was built,

that they gave a building permit within three weeks,

which is very fast, because they thought it wouldn't be built.

And now that you are here,

and you're very much part of this village,

do the people in the village accept you, and like this house?

I think so. We had an open door for one day, when it was finished,

and we expected, like 50 or 60 people,

but it turned out that one third of the village came, over 350 people.

-That's a lot of cups of tea!

-So they were curious, they were curious.

Yeah.

So this is a really beautiful space,

I mean, this is so sensual, you know, bathed in this pink light.

I love it, that's the mirror, isn't it, from the kitchen?

Yeah. One-way mirror.

-Yeah.

-But actually it shows that you don't always need lots of daylight,

but you need the quality of light, and this has a very, sort of,

serene quality, again.

Into the light.

Yeah, this is the, you could say, architectural bedroom.

Look at that. Oh! That's beautiful,

that's beautiful. That's just Switzerland in a picture frame.

Yeah. Yeah, it's really the mountain we framed here.

I love the, sort of, ad hoc-ness of this.

The funny thing is, if you find a Japanese closet like this,

that fits up to three millimetres to the house you already built...

So it had to be this one.

So had you made any plans for steps?

No, we forgot a lot in this house while designing!

I really like that idea, that, in fact,

creativity sometimes comes out of mistakes, unplanned things.

Some of the best things we didn't design, they just happened.

I love this bedroom, this is so secret-y bedroom.

But, you know, that's why architecture's not so important,

it's the bed linen, at the end of the day!

CAROLINE LAUGHS

Oh, that's good, very good.

How much pleasure do you get from coming here?

Oh, a lot. That's why we come as often as we can.

I think the main thing is

that it's really completely different from being

-in the big city.

-When you first walked in today, Piers,

I've never seen you react in quite the same way.

-What was it?

-I did, I guess I instinctively responded to

the space, and atmosphere, and drama.

But do you know why?

Because architecture nowadays is too much about what you see,

and the nice thing of an underground house is you can't get an image from

this house, because the only thing you see is this hole.

So, you have to explore it, and to undergo it,

which is different from looking at only.

Whereas this is rare, in that we can never judge it as an object.

The only reason we were able to buy the land was that the old farmer

didn't want to sell... He wanted to sell the land,

but every time there was almost a sale, he backed out,

and we didn't understand why from other people before us.

But then I asked him can we keep the barn?

And then the old man said, "Ah, you want to keep the barn?

"Then I want to sell." So it turned out that he never wanted to sell

because of destructing his old barn.

But that's so moving.

Has that farmer been back to see the house?

Yeah, yeah, he came in, two sticks, 93 years old.

And he was sitting very proudly here at the table while these 350 people

from the village also entered the house.

Yeah, that's too hot for me.

-It's perfect for me.

-Yeah, but it's too hot for me!

How about we grab some water? Can we use this?

Yeah, this is a well we struck when we built the house.

And, so, this is just beautiful drinking water?

It's perfect drinking water.

Six litres per minute.

-Really?

-Yeah. It's ten degrees, summer and winter.

Oh, God, it's beautiful water.

-Perfect.

-And one thing is missing.

Oh! This house has got absolutely everything.

Now I realise I didn't bring my swimmers.

-I'll get in in my undies.

-All right.

-It is quite warm, actually.

-Come and sit here.

Come and sit this side. That side is very hot, isn't it, Piers?

Too hot for you, Piers?!

-All right?!

-It's perfect, actually.

-Do you want a little dribble?

-Lovely. Yes, please.

-That'll do you.

-A little dribble of pleasure.

-Thank you.

-Ooh!

Everything about this house delights me.

The entrance, the coming in, the fact that it's an underground house,

which really surprises me.

Yeah, not many buildings make me lose or forget my professional self

and actually just experience it in all it's sort of dramatic glory.

And this one, I really did.

Cheers.

I'm absolutely poached!

Our next underground house takes us down under

to New Zealand's South Island.

The sunlight on these peaks is really heavenly.

We're heading to a home built on an exposed plot of untamed wilderness.

The owner wanted a peaceful retreat to retire to,

where she could connect with this stunning scenery.

Really, it's sublime, isn't it?

Yeah, it's beautiful.

The challenge for the design director was to create

a relaxing space in this remote environment,

which would enhance the raw landscape, not destroy it.

Critically, this place is so beautiful, it's so fragile,

the natural beauty of this place,

that this house couldn't begin to compete with this scenery.

In this conflict of house versus scenery,

the design director needed to do something different.

As he was building in New Zealand,

a country which embraces architectural innovation,

he decided to design a house underground to soften the impact

a structure would have on this undulating landscape.

It must be rather nice for architects here

not to be hidebound by that massive

weight of history on their shoulders, like Georgian buildings,

-thatched cottages, and all that.

-Completely.

They don't have any of that stuff to kind of deal with, do they?

None. I'm throttled by that where I am.

I live near Bath, and everything that you build,

you have to consider in the context

of something that was built 200 years ago.

And it's almost like that period in time has to be frozen in aspic

forever. But they have none of those preconceptions here.

You can build anything.

But the critical thing is,

it's got to belong in terms of how it relates to nature.

Now I can see a little sort of boomerang shape,

a little wing shape,

on the right. I think this might be where we're going, Piers.

Hang on, hang on. Yeah, here, yeah.

-Right.

-The glimpse I had, it looks like a little bird has landed.

-There we are.

-You can't get more discreet than that, can you?

That's a little hidden house tucked into a hill.

I like that very much.

-Shall we have a look?

-Let's.

Wonderful views, aren't they?

It's lovely, isn't it? This is the flight path into Queenstown.

There's a plane coming in, Caroline.

The landscape here has a raw elegance.

But with this natural splendour

comes the threat of natural disaster.

Despite its weightless appearance,

this house has been designed and heavily engineered to withstand

the threat of earthquakes.

I'm really interested in how this big wing of a roof just sits very

delicately, as if it's floating.

It's like a kite. That's what it reminds me of.

A tiny delicate edge that looks fragile, but, actually, remember,

is designed to resist seismic forces.

My father was in the RAF.

And when I was a little girl he used to make me paper planes.

-Did he?

-Almost exactly that shape.

As this building is mostly hidden underground,

it allows the landscape to take centre stage.

However, I'm intrigued that this house doesn't give away its

subterranean qualities at first glance.

I'm going to have to go up and have a look and get my bearings,

because I can't quite work out what is where.

-I'll see you in a bit.

-OK.

Looking down here, I can already see different levels

that really are underground.

I think this house is all about the landscape and nothing else,

because standing here now,

with the sun rising over the top of that mountain,

it shows that houses aren't about creating an impression.

They're about creating atmosphere and rooting you in a landscape.

To nestle the property within the land,

dynamite was used to excavate 5,000 cubic metres of earth and rock,

to create bunkers in the ground.

The floor plan of this three-bedroom house

is separated into two different structures.

A main house with living areas and bedrooms,

and a separate annexe.

The underground areas are constructed from concrete,

with east-facing glass facades to maximise natural light.

The highly engineered wing-shaped roof is made from timber and heavily

reinforced with steel to safeguard it against seismic activity.

I mean, I know it's ostensibly an underground house,

but I don't feel remotely like I'm under the ground.

I feel like I'm almost in the sky.

Well, you're under a wing, aren't you?

Held up by this huge core.

Chosen for its extreme strength and contemporary appearance,

concrete was the primary material used in constructing this house.

Almost 1,000 cubic metres were poured to create

the rock solid floors,

walls and the central hearth structure.

This is a huge block of concrete right in the middle of the house.

This goes right the way down into the underground bit of the house.

And when all this is moving around in an earthquake,

this is the most important part of the building.

It doesn't feel to me as if it could withstand a slight gust of wind.

It's very odd. It feels paper thin and delicate,

but you think it's a rufty, tufty house, is it?

Totally. This is a piece of ground.

This is a rock. And the whole house is made out of concrete.

And concrete is about the strongest material,

but it's also the most thermally efficient material.

So here we are in the middle of winter, and that sun is coming in,

hitting this concrete early in the morning and heating up the house.

So it's a very clever house in terms of how the light works

and how the mass of the concrete does so much,

other than just be nice to look at.

Downstairs, sunken below ground level,

there are two snug bedrooms wrapped in earth on three sides,

but still flooded with daylight.

We're right in the rock now, aren't we?

-Underground?

-Yeah. This is what is great about building in the ground.

All the rooms have direct access

right the way out into the landscape.

But, actually, down here, there is a sense of the house enveloping you,

and really cocooning you.

And this is the bedrock.

This is the ground that they had to hollow out to

make this house. I mean, gosh, that would have taken some doing.

How did they do that, dynamite?

Yeah. Beautiful layered rock strata, isn't it?

What, just blow a massive crater?

Blow a massive hole and fill it full of house.

-Really?

-Yeah. But it's interesting, because the house is quite nestled.

And I think unless you did that,

the house would be perched on the top of this hill

at the mercy of the elements.

This house is very complex in many ways.

It takes on enormous themes of landscape

in this big, expansive wilderness.

But, at its heart, it's a very simple exercise in homemaking.

And at the heart of this house is the hearth, the fireplace.

What the hearth also does is root this house right the way down to

the ground. And what happens is the ground is cut around it to make some

bedrooms, a lot of concrete in the ground here.

And then the roof, very thin edges,

kicks up and is anchored right the way to the top of this hearth.

And then there's the bedrooms, and then there's living spaces above.

And what the sun is then allowed to do,

is to enter around here and go around at the end of the day

to there.

So what you get is a fantastic quality of light in the morning.

And then in the evening, underneath,

all of this. And, really, that's it.

This fantastic hearth that really does everything.

And it's really effective.

I'm off to discover owner Louise's favourite room,

an underground chamber, completely separate from the main house.

Louise calls this her inner sanctum.

And I can see exactly what she means,

because if you're going to have a private space,

somewhere to disappear into

when the family are having a thrashing party over the road,

you want some peace and quiet, this is the perfect place to have it.

You've got a beautiful bed with absolutely magnificent views.

A bath that overlooks the mountain.

And even a fireplace.

I suppose these are built-in wardrobes.

It must be great to have so much space for all your...

No, it's not a built-in wardrobe!

It's a kitchen! It's a kitchen in the bedroom.

Oh, my Lord! That's marvellous.

What else is here? Sorry. Won't be a second.

It's a fridge! I love that!

Again, there's this fantastic use of concrete here.

Just like in the other house.

These are two separate houses.

And then here it's been cut away, so there's a light that's allowed in.

This skylight is created through the concrete.

But what's really incredible to me

is you are suddenly aware of how thick this roof is.

It took owner Louise several years to find this plot of land,

and I'm keen to hear from her and her builder, Nichol Thomson,

what challenges they faced when constructing this home.

What was it about building a house here for you?

For me, personally, it was about not living in the city.

And I guess slow down in some ways.

At what point was the decision made to make this an underground house?

The landscape was the most important part.

And the brief had a sentence in it which was, "Let the land speak."

The interesting thing is when you go through a process like this,

there are so many different kinds of design that you like.

-Yeah.

-So, because the landform here is full of hills,

I really wanted the buildings to sit within the land.

We wanted the buildings to feel as though they had just been planted

into the ground.

So there was an incredible amount of effort that went into

thinking through how that would work.

We are building here in a remote part of New Zealand.

Everything has to be brought in by truck,

often off-loaded two or three times before it arrives here.

Things get broken, things get lost.

The first thing was obviously trying to even work out the volume of earth

that had to be removed to build it into the landscape.

And then we had to use explosives to blow it all out.

So a lot of the rock that came out, you'll see in parts,

retaining walls and things all around the property,

it's all been reused.

Constructing this unconventional house took a team of local craftsmen

three years to complete.

The experimental architecture meant a lot of problem-solving for Nichol.

Were there any points when you thought, "This is a tricky build."

Funnily enough, right at the start when we were troubleshooting...

The concrete's a special sort of a mix.

Concrete is a little bit like a cake,

for want of a better description,

so, essentially, the recipe had to be tried out

over and over and over again.

The aggregates, the stones, the cement percentages, the sand,

everything's quite different here.

We ended up, we had sort of a little sort of concrete graveyard

for a while, with about ten or 12 little...

-Tombstones.

-..tombstones.

It took ten or 12 tries?

Yeah, it took us about six weeks.

And at any point did you think, "Oh, I wish I hadn't start this?"

I think everyone does.

I think construction is stressful, it's tiring.

And the whole time you are looking at the spaces that you've studied

and planned intensely over, going,

"Is it big enough, is it small enough,

"does it feel right?"

And so you run this roller-coaster of emotion through the whole

construction period.

And now it's actually finally built...

-Yes?

-..is there anything you'd change about it?

I'd probably put a few more power points in!

One of the things that fascinates me about this house

is that it takes you underground and cossets you

with this fantastic hearth,

and then it pushes you out into the wilderness.

One minute you feel very, very safe, under the ground,

and the next minute you feel like you're a bird,

soaring above the white peaks of the mountains.

Very clever.

'The last stop on our journey to unearth underground homes takes us

'to the Netherlands, and Piers has insisted we adopt the local method

'of transport.'

Piers, you go ahead because I'm really wobbly!

'We're heading to a Dutch nature reserve,

'just 20 miles out of the city centre.

'This protected woodland is considered a local beauty spot,

'and the perfect escape from the bustle of city life.'

I love that, that you can live in a piece of wilderness but it's only

half an hour from a fantastic cosmopolitan city - Amsterdam.

This is my idea of heaven.

The four bedroom family home

we're visiting is owned by architect Sanne Oomen.

where she lives with her husband, Lucas, and their two children.

This family are passionate about living in a sustainable way.

They undertook the challenge of building a large,

contemporary home embedded in the landscape,

so that it integrates with the local nature reserve.

And, Piers, this is a proper eco-build?

It is, it absolutely is.

It's carbon neutral and is super insulated,

and that's why it's underground,

because they use all the earth to heat it and cool it.

And to build a house that's not visible, of course,

is important when you're dealing with a protected forest,

which this is.

Landscape is everything, I think, for this house.

So it's going to be really interesting to see how it fits in.

Here we are. This is gorgeous.

CAROLINE LAUGHS

I love it already!

Talk about green roof, that's the most bushy, green roof

I've ever seen.

It's a hobbit house!

So many eco-houses are so dry, this is so quirky already.

That's very interesting, because when you think of an eco-house you

suddenly become serious.

-Yeah.

-So, "Oh, no, we're protecting the Earth,

"it's got to be very serious."

-Dry muesli.

-Dry muesli and dripping rainwater.

And, actually, this is just hilarious.

But so much of this is banished from contemporary architecture -

humour, wit, life, and this is so verdant and bushy.

It's wonderful, look at it!

"Welcome...

"Mel..Melle, Mats..."

Oh, this is the children... "Melle, Mats,

"Sonne and Lucas.

"All living here."

It's very stylish, isn't it?

Very stylish, the arrow is very stylish.

I wonder what's behind here.

-We can find out because I've got the key to the door.

-The buzzer.

There we are.

-This is great.

-Oh, look!

Now, listen, I'm thrilled to see this.

I think it's so lovely to see people using things in a new and kind of

-fun way.

-Yes. This is stuffed full of things, this house, isn't it?

Look, that's beautiful.

I can hear you.

Do you know, that reminds me, that reminds me of an old friend...

There's so much to look at.

I already want to know what that is.

That's a light into the basement,

I know that without even going down there.

So that light is coming straight downstairs into the basement?

-Straight downstairs.

-Because, oh, God, we're underground, that's why,

-I've just realised.

-Yes.

-So that is in the surface of the garden

that we've just walked through.

-Yeah.

-And suddenly, opening up, and, look, we're outside again.

Piers, this is so exciting.

I love it, I love it.

I love the way they live in it.

Yes, we're underground,

we're underneath that roof at the moment but I don't feel it at all,

because we're connected both by those skylights there

and then straight out the front there.

And what a brilliant panorama of this incredible woodland.

I'm very excited.

Me too, I don't know where to go.

Let's go down there!

This eco-home was designed to be part of the natural environment

and to champion sustainable principles.

After deep excavation and the laying of concrete foundations,

the bedrooms and bathrooms were stacked across three floors

on the north side of the building.

A large, open-plan living space inhabits the south.

From the north side, the entire building is embedded

in earth and greenery,

for natural insulation and camouflage.

The south facing glass facade and a series of skylights bring natural

light into even the deepest parts of the house.

The interior of this home is crammed full of the art the couple have

collected and sits alongside bespoke, handcrafted furniture,

made from reclaimed and up-cycled objects and materials.

And, look, your taxi's here!

That's comedy, isn't it?

-That's a Daimler.

-It is.

What's brilliant, this furniture is actually upside down

and on its side, and it's about, I think,

saying take a look at things from a different perspective.

Let's turn this on its head.

A lot of architects did this in the '70s.

They put radiators on the ceiling and at strange angles and things.

They've got it right here.

They know how to do what's practical,

but to make it beautiful, and funny, and clever,

and interesting, and great to use.

This eclectic mix of up-cycled furnishings

are a stunning example of great design,

fused with zero waste eco-principles.

The centrepiece of the whole house is this big Finnish...? Finn oven?

Finn - F-I-N-N, as in Finnish,

and the principle is that the flue snakes around

to make sure that all of the heat, 90% of it, stays in here.

So, they're not just pipes that go up,

and therefore you lose all the heat out the top?

This actually stays in the body of the oven?

And because it's made out of concrete,

this will stay warm probably for 12 hours after the fire goes out.

Is this ancient or modern?

It's an ancient principle, but used in a 21st-century house.

Alongside the Finn oven,

the house is heated by a wood pellet boiler system

and solar panels placed due south, to maximise the sun's rays.

This provides enough renewable electricity

to power the entire house and the family's electric car

all year round.

Even the orientation of the house is positioned

with environmental sensitivity.

There's clearly a hierarchy of the spaces,

so clearly the main spaces that get the light and height face south,

face the view, and that's where you live.

Then the less important spaces buried at the back,

because they don't need the light.

But here, also, these roof lights let in tonnes of light.

A roof light lets in between three and six times as much light

-as a window.

-Really?

-Seriously, because you get the sky coming in.

-I never knew that!

-And it's flooded with light up there,

just from a couple of roof lights.

But it's chock full of surprises, isn't it?

Oh!

You knew that was going to happen!

SHE GASPS

Oh...

This is another world in here.

And look how thick that bit of ground is up to the sky.

That's how far we are underground.

PATTERING

I can hear the rain.

And even with the rain, you can feel the silence.

It's the perfect bedroom.

WHIRRING

This house is rich with layers of ideas and complexity,

but, at its heart, it's a very simple building.

You have some little spaces stacked on top of one another,

that then protect one big space,

which is where most of the living happens,

and you then take the eaves to make sure that summer sun, which is hot,

can't enter the building,

but winter sun can enter right into the back of the building.

And what you do then

is to take all of the earth and mound it up around the house,

as thick as possible, to make it protected from all the cold,

and earth is actually a very good insulator

when you mound it up really thick.

Earth, when you get down to a certain thickness,

is a stable temperature.

Then, of course, the winter sun

floods in and the summer sun is kept out.

The back of the house then has these little rooms,

these little cellular spaces - utilities, bathrooms -

that are buried in the back of the house,

where you don't need the light.

I love these old doors, set into these modern walls.

This is adorable, this room, it's adorable.

It's obviously a child's bedroom.

It's so lovely.

With a little place for some little tacker to sit in this

beautiful, fascinating, bulbous little window on the world.

Sonne and Lucas spent four years

designing and building their underground home,

with friends and architects Oscar Vos and Thomas Dieben.

The choice to build a house underground,

where did that come from?

My family name is Mole,

all the family living...

No. We just wanted to build a sustainable home.

From the start, we had this sketch of a house,

with a big space like a hole,

and it was my first build and I didn't want to do it alone,

so I decided to ask friends from Delft, from university,

to do it with me.

I was actually quite nervous also about how it would be,

and also about the technical parts.

We were building it during the financial crisis,

so a lot of contractors fell down.

It was hard labour, and a lot of blood, sweat and tears.

The basement was sort of extra,

because at first we couldn't dig in the ground.

Why?

We weren't allowed because it's a winning area, it was not allowed.

How did you get round that?

We told them it's really silly,

you are yourself digging holes to search for the water, 40 metres...

And a big swimming pool, a public swimming pool here.

-And they're telling us we're not allowed.

-Yeah.

And then they changed their own regulations and we were allowed to.

So then we could dig, and then we said we want a basement,

and a very big basement.

Did your client interfere with your work quite a lot?

All the time!

-All the time, yeah.

-But never fights.

All the time bigger and more special.

We had to make it possible.

Like starting architects,

they want to make a clean building with empty and...

-No, that's not true.

-..and white walls.

-No, no, no, no, no.

-Most architects do!

So it will fit in all the architecture magazines.

-Absolutely.

-And I wanted crazy stuff.

Most architects are quite nervous

about that kind of bricolage of ideas.

-But I love it.

-Me too.

Who did you go to about the budget, who did you talk to?

Because client-architect budget discussions are always difficult,

but when you're the client and the architect,

how did you have the budget discussions?

Yeah, how did we do that?

We never talked about the budget.

We just wanted to do it.

Maybe you need to talk about it now!

But what's really interesting is you have a super sustainable house that

uses very little energy, but you still have a Daimler.

Yeah, in Amsterdam you can do anything on your bike,

or with a tram, and we said to each other,

yeah, but we're going to build a sustainable house

and now we're going to

drive each day with a 25-year-old car, five-and-a-half litre engine.

I don't think Mother Earth will like it.

So we gave her a new life, as a cupboard in the kitchen.

And there was this big crane to put it in.

It was snowing in the winter...

She went in through the roof, through the last hole in the roof.

So she can never go out.

She had to die for this green dream.

What's extraordinary is that when we arrived here,

we looked up at that door and we had no idea

what lay behind it.

It's a world of make-believe, but it's real.

It's real, and, also, I get a very real sense that it's actually

sort of the future of the way we're going to live.

Because it reclaims what it is to live sustainably.

But it's also...it's retained its sense of humour,

and its joie de vivre,

its joy in family life.